Automated robots and robotic devices are becoming more prevalent today and are used to perform tasks traditionally considered mundane, time-consuming, or dangerous. As the programming technology increases, so too does the demand for robotic devices that require a minimum of human interaction for tasks such as robot refueling, testing, and servicing. A goal is a robot that could be configured a single time, which would then operate autonomously, without any need for human assistance or intervention.
Robotic devices and associated controls, navigational systems, and other related systems moving in this direction are being developed. For example, U.S. Pat. No. 6,594,844 discloses a Robot Obstacle Detection System, the disclosure of which is hereby incorporated by reference in its entirety. Additional robot control and navigation systems are disclosed in U.S. patent application Ser. Nos. 10/167,851, 10/056,804, 10/696,456, 10/661,835, and 10/320,729 the disclosures of which are hereby incorporated by reference in their entireties.
Generally, autonomous robotic devices include an on-board power unit (usually a battery) that is recharged at a base or docking station. The types of charging stations and methods used by robots in finding or docking with them (e.g., radio signals, dead reckoning, ultrasonic beams, infrared beams coupled with radio signals, etc.) vary greatly in both effectiveness and application. Wires buried below the surface on which the robot operates are common, but are obviously limited in application, as it is costly to install guide wires within the floor of a building or below a road surface. If installed on the surface, the guide wires may be damaged by the robot itself or other traffic. Moreover, the wires need to be moved when the base station is relocated. A base station that emits a beam or beacon to attract the robotic device is, therefore, more desirable. Such devices, however, still exhibit numerous operational limitations.
Base stations that utilize emitted signals often still require additional safeguards to ensure proper mating between the robot and base station and, therefore, safe and effective charging. Some require mechanical locking devices to prevent dislocation of the robot during charging, or other components such as raised guiding surfaces to direct the robot into contact with the station. Such components can increase the size of the base station while decreasing the aesthetics, important considerations for automated robots directed at the consumer market. An increase in base station size also typically makes unobtrusive placement in the home more difficult and decreases the floor area available for cleaning. Additionally, existing base stations generally lack the ability to protect themselves from contact with the robot during operation, increasing the likelihood of damage to either the station or robot, or dislocation of the base station. Such an unintentional collision may require human intervention to reposition the base station or repair a damaged component.
These limitations are, at present, a hurdle to creating a truly independent autonomous robot, free from human interaction. There is, therefore, a need for a robot and base station that can ensure proper mating regardless of location of the base station. Moreover, a system that can prevent inadvertent dislocation of the base station by eliminating collisions between the station and robot is desirable.